In Britain, homeowners can buy a solar systems without upfront costs -- they can get a loan from the government and get paid for sending excess energy to the grid.

Prices have dropped to the point where the payback period is just seven years, he says, and an average family will save 50 percent on their utility bill. It costs $9,200 for a 3.36 kilowatt system in the U.K., compared to $13,000 in the U.S.

Currently, IKEA gets 27 percent of its electricity from renewable energy. It owns six wind farms in Europe and solar powers 70 percent of its stores and distribution centers in the U.S., many of which are the largest commercial solar installations in those states. It ranks No. 4 for U.S. commercial solar installations.